Passengers using elevators can give erroneous elevator calls for many different reasons. A passenger can, for example, accidentally give a destination call to a floor to which he/she is not traveling. In this case he/she has to give a new call to the floor to which he/she is actually going. Some passengers can also deliberately give an erroneous call e.g. in order to receive an empty elevator car for their use. In some cases malicious damage can even be related to calls, e.g. when a person in an elevator car presses all the call pushbuttons and immediately leaves the elevator car. Calls erroneously given in elevator systems according to prior art are generally served as also the other calls, as a consequence of which the transport capacity of the elevator systems declines and the arrival of passengers at their destination is delayed. Another problem is that a passenger that gave an erroneous call can receive a special service, which has an adverse effect on the service received by other passengers. There is thus a need for a solution that identifies and, if necessary, changes or removes erroneous calls in an elevator system.